Weighing and balancing of connecting rod, pistons, rings, wrist pin

[Pete]

Originally Posted by Richard Knight

Pete, thanks. Of all the engines I have had balanced I have never seen a crank spun up. Interesting about the resonance. Would you happen to have any video of spinning a crank up? Thanks, rick.

I have seen videos but don't remember where they were.

[Richard Knight]

Pete, I was hoping someone might be willing to put up a video of spinning up a crank or even a show and tell on balancing rods!

[Pete]

Originally Posted by Richard Knight

Pete, thanks. Of all the engines I have had balanced I have never seen a crank spun up. Interesting about the resonance. Would you happen to have any video of spinning a crank up? Thanks, rick.

Here's a video on Youtube that covers the basic process.
Minor details will vary with type of engine and model of balancer.

https://youtu.be/zwDRGNNl5qk

[old31]

Follow up:

I balanced the connecting rods (off by 8 grams) pistons (off by 6 grams) wrist pins ( off by 7 grams) and the connecting rod end caps (off by 12 grams)

That's a total of 33 grams that i zeroed out. l used a scale that claims it was accurate within 1 gram. i used a scale and did not use the balancing tool that weighs the ends of the rods separately.

This may not have been the best way, but it is certainly better than the way it was in the engine before i took it apart.

[Richard Knight]

Thanks Pete, interesting video.

[Dodge]

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John,
I was wondering if anyone was going to do a modern 2up 2down motor.
How did that thing run?

[johnneilson]

Originally Posted by Dodge

John,
I was wondering if anyone was going to do a modern 2up 2down motor.
How did that thing run?

It had moments of greatness, then well, you know. It showed pretty well on the dyno during break in but didn't beat it too much.

We had issues with ignition and injection in the car and that sidelined the project.

The plan is to either run it in a Miller 2 port or another flathead, but that will be determined later.

John

[Richard Knight]

It seems as though what I have felt in decelaration is the engine rpm passing through a resonant frequency? So if the rotating mass is lightened does this change the resonant frequencies to slightly higher rpms. Has anyone spun up a burtz rotating assembly ? And determined where the resonant frequencies are????